The present embodiments relate to acoustic radiation force imaging. In particular, the present embodiments relate to motion correction in acoustic radiation force imaging.
Acoustic radiation force imaging indicates the viscoelastic property of tissue. Tissue displacement is caused by a wave generated from a stress, such as an acoustic force radiation impulse (ARFI). The tissue response to the wave is tracked over time. Tissue deformation parameters, such as shear wave propagation parameters, are secondary order estimates from phase or displacement of the tracked response.
Acoustic radiation force imaging is susceptible to motion artifacts. The patient may move, the transducer probe may move, and/or anatomy may move. These motions contribute to the displacements and/or resulting parameters. The result is low quality, biased, low repeatability acoustic radiation force imaging. Physiological and transducer motion is inevitable during in-vivo scans and may cause large errors in the estimates of tissue mechanical parameters.
Since tracking is used, motion correction may be applied to frames of echo data prior to determining the displacement. The motion correction may remove some undesired distortions, but does not deal with out-of-plane motion. Motion from the tissue not subjected to the wave caused by the stress may be used to estimate undesired motion, which is then removed from the displacements caused by the wave. Where the undesired motion is different during the wave propagation or at the measurement location, this removal may not be accurate or may introduce error.